Overview

Asynchronous Transfer Mode (ATM) is a data protocol based on transmitting data in small “cells” or packets over Wide Area Networks (WAN). It is designed to carry video, voice and data traffic from customer Local Area Networks (LAN), by encapsulating (wrapping up) the traffic in ATM fixed length cells, to the Wide Area Networks (WAN).

ATM Networks were introduced to the Australian market in mid 1990’s. The networks were designed to effectively combine video, voice and data traffic on a single network with guaranteed performance for each traffic type. ATM is ideally suited for traffic separation using Virtual Paths and Virtual Circuits and connecting individual sites over the network.

The network is designed to operate principally for link speeds of 2Mbps and higher. Although pure ATM networks are very rare these days, they are still frequently deployed as the access technology for the Head Office Hub, running at 34Mbps, 45Mbps or 155Mbps link speeds. The protocol readily interfaces with Frame Relay as the Primus network can dynamically translate the ATM cells to Frame Relay and back.

All Digital Subscriber Line (DSL) access uses ATM as the transfer protocol over the copper pairs, making ATM one of the most broadly distributed access technologies. When combined with Managed Router Services, ATM is the most common access technology used for access circuits into Private IP and MPLS (Multi Protocol Label Switching) networks.

The key advantage of ATM is the ability to combine, on a single access, delay sensitive Video traffic, with equally sensitive Voice traffic and more delay tolerant Data traffic. ATM link speeds should be defined in Cells Per Second rates, but in practical terms, they are translated to Kbps (Kilobits per second) or Mbps (Megabits per second) speeds. Similarly to Frame Relay, they have a concept of Committed Information Rate (CIR) that permits customers to only buy the “average” bandwidth requirement to a given site, while the network permits the link to “burst” (transmit data at a higher rate) for short periods of time, helping to reduce network costs while providing a better network performance.

Other Classes of service on the ATM network are:

• Constant Bit Rate (CBR) for video traffic,
• Variable Bit Rate - Real Time (VBR-rt) for voice traffic,
• Variable Bit Rate – Non-Real Time (VBR-nrt) for data traffic,
• Available Bit Rate (ABR) and Unlimited Bit Rate (UBR) typically designed for internet type “best effort” applications.

Primus ATM network solutions are designed in consultation with the customer via the Primus Professional Services Group (PSG). PSG will analyse your requirements and design a solution for your business and data networking needs.

Features & Benefits

• Network provides point to point or point to multi-point type networks;
• ATM is ideal for building hub and spoke and partially meshed networks;
• ATM can form part of hybrid network designs with Frame Relay and MPLS (PIPN) networks;
• ATM provides high speed access to the network;
• Sites are defined by Access Link Speed at a given site and Committed Information Rate (CIR) from the site to the Central Site (the hub) as well as a class of service type for each logical link;
• Access Link speed starts from 2Mbps. Up to 4 x 2Mbps links can be bonded together to form 8Mbps ATM access. Other access speeds include 34Mbps, 45Mbps and 155Mbps. Higher speeds are also available;
• ATM scales and performs well under heavy utilisation;
• ATM provides extremely good quality of service management for delay or jitter sensitive applications – ideal for voice and video;
• ATM is an effective solution for multiplexing of diverse traffic streams within the one high speed access.

Pricing

The pricing of ATM services consists of three components:

• Network Fees
• Access Fees
• Equipment or Router Fees

ATM Network Fees – this is the cost of the guaranteed bandwidth that has been made available by the network. The pricing is based on the class of service as well as network costs due to distance and geography in maintaining the ATM network to the specified locations.

ATM Access Cost – this is the cost of the access tail that is used to connect the customer site to the network. Access tails suitable for ATM transmission include SHDSL, E1, E3, T3, and dark fibre.

Equipment or Router Fees – this is the cost of the supply, installation and configuration of the equipment, as well as the ongoing maintenance, management and monitoring of the device and the rest of the network. Primus currently supports the use of Cisco and Adtran routers.

As an ATM network is a custom designed solution, please contact Primus on 1300 65 44 24 to discuss your data networking needs.